摘要
江汉平原某些地区地下水已受到砷的严重污染,探讨高砷地下水的形成机制十分必要。采集江汉平原高砷区不同深度(20m、50m、100m、130m、160m和225m)的高砷沉积物样品,对其进行了地球化学成分特征分析,并通过实验室模拟试验对微生物介导的高砷沉积物中砷的溶解与转化以及来源进行了分析。地球化学分析表明:高砷沉积物中不可溶性砷和铁的平均含量分别为27.57mg/kg和21.06g/kg;实验室模拟试验表明:微生物群落可以明显促进高砷沉积物中不可溶性砷和铁的溶解与释放;砷顺序提取试验结果表明:沉积物中34.5%的不可溶性砷为无定形铁锰氧化物结合态砷;进一步的相关性分析表明:试验体系中可溶性砷的含量与沉积物中无定形铁锰氧化物结合态砷密切相关。这些结果表明:微生物可以促进高砷沉积物中不可溶性砷的溶解与释放,且释放的砷主要来自于沉积物中无定形铁锰氧化物的还原与溶解。
The groundwater in some areas of Jianghan Plain is severely contaminated by arsenic,hence,it is necessary to discuss the formation mechanism of the arsenic rich groudwater.This paper collects high arsenic sediment samples from different depths(20m,50m,100m,130m,160m and225m)in Jianghan Plain to conduct the geochemical component analysis and explores the mobilization,transformation and release of soluble arsenic in arsenic rich sediments mediated by microorganisms through laboratory simulation test.The geochemical analysis indicates that the sediment samples contain relatively high contents of insoluble arsenic(27.57mg/kg on average)and iron(21.06g/kg on average).Microcosm assays indicate that microbial communities in the sediment samples significantly increase the release of insoluble arsenic and iron;sequential extraction experiment shows that34.5%of arsenic is attached to amorphous Fe and Mn oxides in the sediments.Correlation analysis shows that the concentration of soluble arsenic is closely related to the arsenic attached to amorphous Fe and Mn oxides in the sediments.The results show that microorganisms can increase the dissolution and release of insoluble arsenic and iron,and the soluble arsenic mainly comes from the reduction and dissolution of amorphous Fe and Mn oxides.
作者
王家宁
石晚霞
祝贤彬
何忠
WANG Jianing;SHI Wanxia;ZHU Xianbin;HE Zhong(School of Envrionmental Studies,China University of Geosciences,Wuhan 430074,China)
出处
《安全与环境工程》
CAS
2017年第6期8-13,共6页
Safety and Environmental Engineering
基金
国家自然科学基金项目(41272257)
关键词
高砷沉积物
微生物群落
不可溶性砷的溶解与释放
无定形铁锰氧化物结合态砷
arsenic rich sediment
microbial community
dissolution and release of soluble arsenic
arsenic attached to amorphous Fe and Mn oxides
